Farmland habitats and biodiversity part 2

what are the different types of grassland?

• natural,

• semi-natural,

• unimproved,

• semi-improved,

• improved meadows,

• pastures,

• permanent pastures,

• leys,

what are virtually all British grasslands and all British habitats?

a product of human actions and management

what are silage grasslands?

the most agriculturally productive, reliable and the forage they produce is of high nutritional quality

what negatives are there will silage grasslands?

they are extremely low in botanical, invertebrate and vertebrate diversity

what type of grasslands are the most species diverse?

‘traditional’ hay meadows

what are the negatives of ‘traditional’ hay meadows?

they are relatively low in productivity and don’t fir into modern intensive agricultural systems

what do farmers work hard to do?

create and maintain grassland productivity and forage quality

what is low intensity grazing and what does it allow for?

the gradual removal of material which allows selective grazing, slow structural changes and potential scrub encroachment

what is high intensity grazing?

the rapid removal of material which allows for non-selective grazing

what may high intensity grazing cause?

poaching

How do cattle graze?

pulling and grabbing with their tongue rather than nibbling

what does cattle grazing produce?

a tussocky sward

what does cattle do which allows other species to invade?

damage the sward with their feet

how does sheep grazing affect the soil?

they compact the soil

what does sheep grazing cause for the sward?

tight uniform sward due to them nibbling

what’s fertility like in improved grasslands?

high

what’s fertility like in unimproved grasslands?

low

what qualities does improved grassland have?

• above ground competition for light,

• high productivity,

what species are present in improved grasslands?

tall growing species or those tolerant to high grazing pressure

what qualities are there of unimproved grassland?

• below ground competition for nutrients,

• low productivity

what species are grown in unimproved grasslands?

low growing species tolerant to low nutrients

what’s the typical species richness in grasslands where pH>7?

30 spp./m²

what’s the typical species richness of grasslands with pH between 5.5-7?

20 spp./m²

what’s the typical species richness for grasslands with a pH <5.5?

10 spp./m²

what does calcicolous mean?

grassland with pH>7

what does mesotrophic mean?

grassland with pH between 5.5-7

what does calcifugous mean?

grassland with a pH <5.5

what is grassland type determined by?

• site factors,

• past management,

• present management,

where does livestock grazing dominate agricultural practices?

at higher altitudes

what’s most commonly used to cut-off between upland and lowland areas?

the 250m contour

removal of grazing leads to changes in vegetation through what process?

succession

when will a ‘climax community’ be reached?

when vegetation is allowed to develop through succession

Historically, how was UK tree cover increased?

through plantation woodland

what is a notable storage of carbon in British habitats?

within peatland and wetlands

how many tonnes of carbon dioxide does damaged or drained peatlands worldwide emit annually?

at least 2 billion

what are mires?

extensive areas of permanently wet peat

what are 2 main features of mires?

fens and bogs

what is a fen?

a base rich or alkaline mesotrophic (mid nutrient level) or even eutrophic (high nutrient level)

what is a bog?

acidic and oligotrophic (nutrient poor)

what reduces the amount of sponges to slow down the flow of water?

conversion of peat bogs to farmland and drainage of farmland further upstream

what do peatlands and wetlands do?

store or at least slow down the flow of water through a landscape

what’s Sphagnum moss?

a ‘habitat engineer’ which changes the local environment whilst growing

what was irrigation designed to do?

deliberately allow relatively warm, nutrient carrying water to trickle over the soil surface